Cool. Sometimes growing means to reduce the number of code
lines. Today is an example. I integrated the lino.mixins.repairable
module into lino.modlib.checkdata.

Instead of writing a get_repairable_problems method, we write
Checker
classes and activate them. And
the get_checkdata_problems
method must yield (fixable, message) tuples instead of simple
strings. And the Problem model has a new field
fixable.